VIMOS Documentation

In this page, you will find all the manuals needed to prepare and analyze your observations with VIMOS.
Please be sure to download the version corresponding to the period in which the observations will take place.

All the manuals are in Adobe's Acrobat format.

VIMOS User's Manual

All the information about the instrument itself, its modes and their characteristics as well as the informations on the acquisition, observation and nighttime calibrations templates.

VIMOS will be decommissioned at the end of Period 100 or early in Period 101, and is therefore not offered in Period 101.

Period 95, for P95 phase 2. Note the update regarding the rules for attached MOS nighttime calibrations (Sect. 3.5.8.), based on the analysis in Wolff et al. (2014) as summarised further down on this page.

Period 95, for P95 phase 1. Note the change about pre-imaging: to be done as loose OBs, not in concatenations.

Period 94, for P94 phase 2. Note one change relevant for Phase 2: users are requested to specify standard star requirements for pre-imaging.

VIMOS Pipeline User Manual

The (quite outdated) data reduction cookbook (VLT-MAN-ESO-14600-4033) is available here.

Wavelength accuracy without attached MOS calibrations (P95 onwards)

In the following memo Wolff et al. (2014) we investigate the accuracy in wavelength calibration that can be achieved when skipping the attached MOS nighttime calibrations, and thus calibrating nighttime observations with daytime calibrations only. We find that for grisms LR_blue, LR_red, HR_red, the wavelength accuracy is about 0.5-1.0 pixel, whereas it degrades to 1.0-2.0 pixel accuracy for grisms HR_blue, MR, and HR_orange. This is caused by residual flexure effects that cannot be fully corrected with the current Active Flexure Compensation mechanism. Internal accuracy not considering flexure effects are of order 0.3 pixels.

As a consequence, rules in P2PP for attached MOS calibrations have been updated for P95: for the more accurate grisms LR_blue, LR_red and HR_red (<1 pixel) the previously implemented waivable error has been converted to a warning. That is, users can create their MOS OBs without attached calibrations, but need to check that their science case can accept wavelength accuracies of 0.5-1.0 pixels. For the less accurate grisms HR_Blue, MR, and HR_orange the waivable error remains in place.

Wolff et al. (2014) memo on the accuracy in wavelength calibration that can be achieved when skipping the attached MOS nighttime calibrations.